A broad integrated program for the study of the immunological response to malignant cells is proposed. Because of the intrinsic complications of the problem, it is separated with a series of narrower, definable questions based on simplified model systems. The major specific questions to be studied are: 1. Genetic relation of the immunological response to self antigens; 2. Regulation of tumor growth by syngeneic antibody of different classes; 3. Effect of modification of lymphocyte membranes on lymphocyte reactivity; 4. Liposomes coated with antibodies specific for cell surface antigens to deliver chemotherapeutic agents; 5. The isolation and characterization of tumor associated antigens from urine or other body fluids of human patients and experimental animals.